2000 Jeep Grand Cherokee - heat not working

The blower worked “sort-of” for a few months and completely stopped working yesterday. The fan does not work no matter what heat setting you put it on. Is it the motor or the relay…

I would suspect the relay first. You could tie power directly to the motor to verify it is ok.

Let me guess. The fan stopped running on lower speeds one then the next and now it does not run at all.

That means the resistor block is out and likely the blower fan motor has failed and that is what has blown out the resistor block.